First, the cultivation technology of Siniperca chuatsi fry
Culture conditions:
1. Environmental requirements: the pond requires a sandy bottom, less silt, an area of 2 ~ 3 mu, a water depth of more than 1.5 m, convenient irrigation and drainage, light water quality, no sewage inflow and a small number of submerged weeds. Newly opened ponds depend on the soil quality, and acidic ponds and muddy ponds are not suitable for raising mandarin fish.
2. Cleaning and disinfection of the pond: Clean the pond with quicklime on April 5th, and pile grass fertilizer at the four corners of the pond around April 10 (if the bottom fertilizer is good, no fertilization is needed) and add 0.8 ~ 1.0m of fresh water to cultivate the water quality and cultivate the natural bait of feed fish.
3. Bait culture: the fish nest (floating handle) containing crucian carp eggs is put into the pond for incubation. Generally, the density of fry is controlled at about 500,000 per mu, and the eggs can be put in 2-3 batches with an interval of one day, so that all the Siniperca chuatsi fry with irregular specifications can have palatable bait.
Cultivation mode:
The newly hatched fry is soft and tender, the individual is smaller than the domestic fish, and the body length is only about 4 mm. After 50-60 hours of cultivation, the body length is 4-5 mm, and the average heart rate is 3 times per second. At this time, the Siniperca chuatsi fry began to eat, that is, entered the summer flower cultivation stage. Since 1990s, the techniques for cultivating Siniperca chuatsi fry have been continuously improved and perfected, and the cultivation methods are various. Production can be summarized as running water and still water cultivation. The survival rate of running water seedling is higher than that of still water seedling.
1. Flowing-water seedling: Flowing-water seedling can be divided into two ways: incubation pond and ring-groove seedling, and the operation is basically the same.
① Culture conditions: the incubation pond (loop) has fresh water quality, large water exchange, balanced water temperature, small temperature difference and rich dissolved oxygen, which meets the environmental requirements for the growth of Siniperca chuatsi fry. This method is often used in production, that is, the Siniperca chuatsi fry hatched in the incubation pond (ring road) continue to be cultured in the original pond (ring road) with artificially controlled water flow.
(2) Stocking density: In the early stage of seedling raising, the stocking density of Siniperca chuatsi fry is generally 0.5 thousand ~10.000 fish /m2, which gradually decreases with the increase of individuals.
③ Cultivation method: During the cultivation of Siniperca chuatsi fry, the incubation tank (circle) 1 time should be changed every 5 days or so according to the specifications, and the sediments on both sides of the bottom of the incubation tank (circle) should be removed at the same time. Siniperca chuatsi fry are greedy, so it is best to stop feeding bait fish a few hours before the hatching tank (loop) turns around to avoid overeating.
2. Still water seedling raising: still water seedling raising is cultivated in fish ponds, cement ponds and cages.
① Culture conditions: The general cement pond is the best pond for breeding Siniperca chuatsi fry, with an area of 30 ~ 50 square meters and a water depth of 0.8 ~ 1 m.. Some artificial reefs simulating natural waters can be set at the bottom of the pond to create a good predation environment for Siniperca chuatsi fry.
② Disinfection stocking: Before stocking fry, the culture pond must be thoroughly cleaned and disinfected. Generally, the stocking density is about 7000 per cubic meter of water. When Siniperca chuatsi grows to about 1.5cm, it will be better to move into a cage for culture.
Feeding:
Mandarin fish is a typical carnivorous fish. Its biological characteristics determine that it eats live fry with its mouth open and eats each other when it is hungry. Therefore, it is one of the key measures to grasp the feeding time accurately, select bait fish and supply palatable bait in time.
1. Feeding time: Organ differentiation and development of Siniperca chuatsi seedlings are closely related to water temperature. Generally, when the water temperature is 23.5 ~ 25℃, 24 ~ 26.5℃ and 26 ~ 29℃, the time for the fertilized eggs of Siniperca chuatsi to develop to feed is 1 12 ~ 650 respectively.
2. Open bait: Whether the size of open bait fry is appropriate directly affects the feeding and survival rate of Siniperca chuatsi fry.
① Selection of open bait: In production, the open bait should be bream, bream, snakehead and other fry with flat fish body and weak swimming ability, especially the live fry that has just been peeled for 8 hours. At this time, the bait fish is easily swallowed by the whole tail of Siniperca chuatsi.
2. It is forbidden to feed the old-mouth fry: If the old-mouth fry is fed, the Siniperca chuatsi fry can only use a small part of the tail of the bait fish, and the rest is often hung on the mouth of the Siniperca chuatsi fry, which not only affects the movement, but also easily decomposes in the water, deteriorates the water quality and even breaks out fish diseases.
(3) Feeding bait on time: If palatable bait fish are not available within 3-5 days after the Chinese mandarin fish fry start feeding, their mobility will suddenly drop, and they will feel dull, thus gradually wasting away and dying, even swallowing and getting stuck with each other because they can't swallow.
3. Bait making: the mouth crack of mandarin fish and the body height of bait fish change constantly with growth. Chinese mandarin fish at different stages need to be fed with bait fry at a certain development stage before they can be swallowed by Chinese mandarin fish.
①60-year-old Siniperca chuatsi fry can only swallow 60-2 16-year-old thin Siniperca chuatsi fry.
②84-year-old Siniperca chuatsi fry can swallow 60-2 16-year-old Megalobrama amblycephala fry.
③ Siniperca chuatsi fry at the age of108 can devour Siniperca chuatsi and Siniperca chuatsi fry at all stages before the age of 2 16, and grass fry at the age of 36 ~ 108.
④ Siniperca chuatsi aged 0/44/kloc can swallow grass seedlings aged 36 ~ 108.
⑤ 144-year-old mandarin fish can swallow 12 ~ 2 16-year-old mandarin fish, mandarin fish, grass carp, carp, silver carp and 24 ~ 108-year-old silver carp.
4, the number of bait
① Feeding amount at different ages: the bait of Siniperca chuatsi larvae at different ages does not meet the specifications of palatable bait fish. At the initial stage of feeding, the feed for each Siniperca chuatsi fry is 2-3 days, 4-5 2-4 days, 8- 12 days, 8-65438+5-8 days.
(2) judging whether the bait is sufficient: the abdomen of Siniperca chuatsi fry fed completely bulges and is prismatic, and the tail handle is slightly arched. In the case of running water, the hungry mandarin fish fry are flat and spread out in the loop to feed, leaning against the inner wall or drifting with the water. According to this, it can be judged whether the bait fish is sufficient.
5. Feeding mode: During the cultivation of summer flowers of Siniperca chuatsi, it can be clearly seen that Siniperca chuatsi eats bait fish from the tail. Often the fish is half in the mouth, half in the mouth, digested while eating, and finally spit out the fish head. Sometimes, the head of bait fish hangs on the spine behind the gill cover of Siniperca chuatsi larvae, which is often mistaken for parasites.
6. Strengthen management: During the cultivation of Siniperca chuatsi fry, it is necessary to carry out meticulous management, thoroughly disinfect the water body, prevent pathogens from being brought into the nursery pond, strictly control the water quality, discharge pollutants in time, cultivate bait fish in time, pay attention to the connection with the cultivation needs of Siniperca chuatsi fry, strictly disinfect the bait fish before feeding, regularly sprinkle drugs into the nursery pond, and do a good job in preventing and treating fish diseases, thus effectively improving the survival rate of Siniperca chuatsi fry.
Second, how to choose mandarin fish
High-quality mandarin fish has prominent eyeball and transparent cornea. Fresh fish eyes are clear and bright, full and full, with prominent eyeballs and clear boundaries between black and white.
The mouth of fresh fish is slightly closed but easily broken, the abdomen is normal and not swollen, and the cloaca hole is white and sunken. Gently press the belly of the fish with your hands, so that no sticky dirty things will overflow from its cloacal hole, including the mouth is clean.
The gills of Siniperca chuatsi are bright red, the gills are clear, the scales are complete and shiny, and they are not easy to fall off. Fresh fish scales are bright and complete, neatly close to the skin, and there will be no sloppy shedding.
The meat of mandarin fish is firm and elastic.
What is the nutritional value of mandarin fish?
Mandarin fish has a flat side and irregular depth, so it is nicknamed Aohua fish, which lives in Heilongjiang and is known as the most beautiful fish species in Heilongjiang. Mandarin fish meat is thick, delicious, fresh, fragrant, tender and smooth. Mandarin fish contains a lot of protein, which is suitable for people with weak health to supplement nutrition. The effect of eating mandarin fish regularly is to clear away heat and replenish blood, strengthen the body, supplement the body function, benefit the stomach and strengthen the spleen.